Ok, so this isn't your normal "I don't know what. why, or how death wobble questions. I did a lift for a friend on her 50k LJ rubi, she wanted to go cheap, so she bought a fat bob's 3" lift that used spacer blocks and bumpstop extensions with new shocks, at the same time we installed 315/75/16's on the stock wheels with a set of rough country hub-centric spacers to let the tires clear the frame. On the first test drive, it had instant death wobble starting at 28mph going to 46mph before it smoothed out. So I nursed it into work and aligned it, rechecked tire balance(which was good), installed a heavier stabilizer shock(which I know is a band-aid). The death wobble has gotten better, not as violent and the window has narrowed to 32mph to 40mph. It's fine above and below these speeds. It doesn't have any bent wheels as checked on the balancer, I've rotated them front to rear and side to side, with no difference in death wobble appearance or harshness. Everything in the frontend is tight, as checked by me and another tech.

So, now where do I go with this thing!!! I know caster is slightly lower than stock, but it doesn't have cam bolts to change it, and with it being a speed related death wobble I'm hard pressed to buy a set and install them for no good result. If it were bump related I'd change the caster. This jeep hasn't ever been offroad in it's life, and hasn't ever had any accidents. I'm pretty much at my wits end with it and work is piling up on my own vehicles.... HELP!!

 

Did you check the torque on the steering linkage. You sound must more informed than me, but that's what I would look at first. Sounds like you're getting harmonic imbalance at 32, corrected by gyroscopic effect over 40.

 

Can you remove the wheel spacers and just drive the set up striaght down the road to see if the wobble goes away?
At three inches of lift did you relocate the front stock track bar?
And if so what happened to the rear if anything.
With 60k on it she could have some play in the stock front track bar as well.

 

Neither has been relocated, as the parts didn't come with the lift. everything in the frontend including the track bars appears to be tight. The axles shifted side to side as expected, but was aligned to track straight. not that the axles were moved, just that everything is set straight ahead. I can't remove the spacers the tires wont clear. I'm stumped by it, and have temporarily moved on tho working on my truck while I wait for some ideas to try next.

 

Have you tried changing the trackbar bolts out with reg grade 8 ones. The stock ones won't torque enough for shit. The torque for it is 90 ftlbs, I go 100 with the 8's

My stock lj had DW, this fixed it. Hell the stock bolts wouldn't even torque to 90, they'd snap off.

 

Well, she decided that she wants to change the setup already after she came back for the weekend and drove it. She's going to have me get rid of the front spacers and do springs to level it out, changing her wheels because she wants black ones, and getting an adjustable front track bar. So after this round of changes I'll report back and let everyone know how I make out. Hopefully she gets the right offset wheels and right height springs.

 

I run 38's with no steering stabelizer and have never had death wobble.

The most common cause of death wobble is loose bolts. #2 is bad bushings, particularly the track bar bushings. I'd head under the rig and re-tighten everything. I'd also use lock tite on it all.

 

ok, so this damn lj has sat in the yard for months while the owner decided what she wanted to do next.. So last week more parts show up. JKS track bar adjustable, dyna beads for the tires, and new black rock wheels. Not that anything was wrong with the old wheels, but she wanted to go black with simulated bead lock. All new parts go on and death wobble is worse than it ever has been. I feel that this yellow LJ is haunting me!! I've gone through every nut and bolt on the front end, checked and rechecked every tie rod end, ball joint, bolt on it. I'm literally ready to unlift it, and send it back to her with a pile of parts in it. At least it would be driveable then. Any new suggestions?

 

either get adjustable front lowers or the cam bolts and dial the caster back to where it needs to be. otherwise enjoy your death machine.

 

I second the adjustable arms. If you really don't want to get these, you can often get away with a little more toe in. Of course, this will wear the tires.

Do it right, and get adjustable arms and run about 6 degree of caster. This will cure the wobble.